I. Technical Field
The present invention relates to a hand-held polishing tool by which a user performs polishing operation. More particularly, the present invention relates to a polishing tool having an oscillating shaft and a polishing member attached to the oscillating shaft, wherein the oscillating shaft is oscillated by means of a motor within a predetermined angular range about an axis of the shaft, whereby the polishing member performs polishing operation.
II. Description of Related Art
Conventionally, a polishing member used in such a polishing tool is generally thin and triangular in shape so that it is possible to easily polish a surface in a narrow portion such as a corner portion of the inner bottom surface of a box-shaped casing. A surface in such a narrow portion is polished by means of a corner portion of the triangular shape (Japanese Unexamined Utility Model Registration Application Publication No. 6-63284). In this case, a polishing tool body is often inclined such that a polishing surface in the corner portion of the polishing member firmly contacts with a to-be-polished surface in a corner portion and the like, and thus the polishing surface in the corner portion of the polishing member is often urged against the to-be-polished surface. Therefore, the polishing surface in the corner portion of the polishing member wears faster than other portions. Thus, the whole of the polishing member needs to be replaced even though the central portion of the polishing member can still be used, resulting in diseconomy.
Further, Japanese Patent No. 2607056 discloses a polishing tool in which the side portion of the triangular polishing member is arc-shaped in order to prevent the oscillating polishing member from hitting hard against a linearly extending side wall of the above-mentioned casing when polishing the inner bottom surface of the box-shaped casing at a portion adjacent to the side wall in a state in which the side portion of the triangular polishing member is adjacent to the side wall.